So, lets put everything together:
1. vCPU 1.3*v, 470FSB x 6, CPU GTL vRef 65x, 1.61 vNB GTL vRef 67x PL8, 1.40 VTT - lockup after no more than 10 minutes.
2. vCPU 1.3*v, 470FSB x 6, CPU GTL vRef 65x, 1.61 vNB GTL vRef 67x PL8, 1.42 VTT - rock stable.
3. vCPU 1.46(measured with multimeter), 470FSB x 8.5, CPU GTL vRef 65x, 1.61 vNB GTL vRef 67x PL8, 1.42 VTT - lockup, same time. => Rising vCPU, rising vNB, rising CPU GTL vRef - doesn't help.

So far, as i said before, it seams, that VTT is the critical value here. 1.42v or 1.36v as Hardware Monitoring measures is near to unsafe values. If i'm 100% sure, that 1.36v measuret in BIOS is the real value all the time, maybe i'll push it more to 1.42v real. If this isn't the case i think it's worthless even trying to find with what VTT case 3 would work. Lowering VTT under 1.36v take me to highest stable FSB at 450. With 470FSB and 1.24v VTT it won't even start to load OS. What is the most stange thing for me here is why rising just the multiplier and applying enough vCPU (1.48 vCPU doesn't help too and i ain't gonna use higher for 24/) it push me back to lockup. I thought that max CPU FSB ot max CPU freq are two separate things.